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Friday, November 4, 2011

CHANCE OF FLARES: NOAA forecasters have upgraded the chance of X-class solar flares today to 20%. The source would be AR1339, one of the biggest sunspots in many years. The active region rotated over the sun's eastern limb two days ago and now it is turning toward Earth.

The sunspot has already unleashed one X-flare on Nov. 3rd around 2027 UT. A movie from NASA's Solar Dynamics Observatory shows the extreme ultraviolet flash:

The flare created waves of ionization in Earth's upper atmosphere, altering the normal propagation of radio waves over Europe and the Americas. In Ireland, the flare's effect was felt even after dark.

A cloud of plasma or "CME" raced away from the blast site at 1100 km/s. The CME is not heading for Earth. It is, however, heading for Mercury and Venus. Click on the arrow to view a movie of the CME's forecast track:

Analysts at the Goddard Space Weather Lab say the CME will hit Mercury on Nov. 4th around 16:14 UT. NASA's MESSENGER probe in orbit around Mercury will be monitoring the effects of the impact. If the CME overwhelms Mercury's relatively weak magnetic field, it could scour material off the planet's surface creating a temporary atmosphere and adding material to Mercury's comet-like tail. The CME should hit Venus on Nov. 5th; the gossamer cloud will probably break harmlessly against the top of planet's ultra-dense atmosphere.

******************************************************************************X-FLARE: Earth-orbiting satellites have just detected an X2-class solar flare. The source is huge sunspot AR1339, described below. Stay tuned for updates.

MAGNIFICENT SUNSPOT: One of the largest sunspots in years is rotating over the sun's northeastern limb. NASA's Solar Dynamics Observatory took this picture of AR1339 during the early hours of Nov. 3rd:

Measuring some 40,000 km wide and at least twice that in length, the sprawling sunspot group is an easy target for backyard solar telescopes. Two or three of the sunspot's dark cores are wider than Earth itself.

Naturally, such a large sunspot has potential for strong flares. NOAA forecasters estimate a 50% chance of M-class solar flares during the next 24 hours. One such eruption has already occured: An M4-flare at 2200 UT on Nov. 2nd produced a bright flash of extreme UV radiation (SDO movie) and hurled a coronal mass ejection (CME) into space. The CME is not heading our way. Future CMEs could have greater effect as AR1339 turns toward Earth in the days ahead.

2011-11-03 15:06 A benevolent monster of a region?
A monster of an active region, NOAA number 11339, has rotated on to the Earth-facing side of the Sun. This is the largest active region in almost seven years, since January 2005. It has produced only a few minor flares so far, but SWPC will be keeping a close eye on it to watch for any threatening behavior. This region is likely to remain a threat for the 11 days or so it will take to rotate back to the far side of the Sun.http://www.swpc.noaa.gov/

UPDATE: 11-4-2011

CHANCE OF FLARES: NOAA forecasters have upgraded the chance of X-class solar flares today to 20%. The source would be AR1339, one of the biggest sunspots in many years. The active region rotated over the sun's eastern limb two days ago and now it is turning toward Earth. Solar flare alerts:text, voice.

The sunspot has already unleashed one X-flare on Nov. 3rd around 2027 UT. A movie from NASA's Solar Dynamics Observatory shows the extreme ultraviolet flash:

The flare created waves of ionization in Earth's upper atmosphere, altering the normal propagation of radio waves over Europe and the Americas. In Ireland, the flare's effect was felt even after dark.

A cloud of plasma or "CME" raced away from the blast site at 1100 km/s. The CME is not heading for Earth. It is, however, heading for Mercury and Venus. Click on the arrow to view a movie of the CME's forecast track:

Analysts at the Goddard Space Weather Lab say the CME will hit Mercury on Nov. 4th around 16:14 UT. NASA's MESSENGER probe in orbit around Mercury will be monitoring the effects of the impact. If the CME overwhelms Mercury's relatively weak magnetic field, it could scour material off the planet's surface creating a temporary atmosphere and adding material to Mercury's comet-like tail. The CME should hit Venus on Nov. 5th; the gossamer cloud will probably break harmlessly against the top of planet's ultra-dense atmosphere.